catch variables should not be flagged as unused with `--noUnusedParamters`

[mhegazy]

        try {
           throw new Error();
        }
        catch (e) {
            return false;
        }

e should not be an error.

[glen-84]

@mhegazy Should this change now that catch clause variables are optional? (and I assume you could also use _e)

Error:

catch (e) { /* `e` not used */ }

Okay:

catch (_e) { /* `e` not used */ }

Okay:

catch { /* `e` not used */ }

[mhegazy]

we can tighten it up now that we have the optional catch clause. we also need to update the quick fix to handle it correctly. a PR would be appreciated.